WFMY News 2's Liz Crawford spoke with High Point Police Chief Marty Sumner about ALPR. Their agency was able to purchase two APLR machines a few years ago. They are mounted on top of two marked police vehicles.

The technology can read several license plates in the area and compare it to the department's database of wanted, lookouts, stolen vehicles and see if there's a match. It does it constantly while the officer is driving around.

"If you have a shooting and you go out and you just do a canvas of the neighborhood, streets around where the shooting occurred. At some point in the future, one of those cars, the fact that it was there may be very important the investigation. You may develop a suspect," explained Chief Sumner.

High Point stores the data for one year. With ALPR, they've located stolen vehicles, they've placed vehicles at certain crime scenes, and they're very helpful during routine license check points.

If the ALPR finds a match, that's not enough for the officer to stop the car. They still have to locate the car, run the tag, and determine it is in fact in violation.

Chief Sumner added, "We don't use it to track people, we don't use it to track people's movements. It's not at all equivalent to a tracker or something that we would put on somebody's car that would likely require a search warrant."

The ACLU of North Carolina is skeptical of the scanners. They think it's an invasion of privacy and crosses the line by storing data for a period of time.

Once an ALPR scans your license plate, it keeps the GPS data for a certain amount of time, depending on how long the law enforcement agency keeps the data.

That gives law enforcement a look inside where you're going and when, from work to home to doctor's appointments or clinics.